Heroin addiction can have devastating social, medical and economic consequences. Methadone maintenance is an effective treatment for heroin addiction, but only about 20 percent of opiate dependent individuals receive it. Naltrexone is an opiate antagonist that could be an effective alternative for many individuals. However, its utility has been limited by poor patient acceptance. Recently developed extended-release depot formulations of naltrexone provide opiate antagonism for up to 6 weeks and simplify naltrexone adherence. However, given the rejection of oral naltrexone by most patients, concurrent behavioral treatment will be needed to encourage patients to take the depot consistently. A randomized study is planned to evaluate the effectiveness of the Therapeutic Workplace in promoting use of depot naltrexone in unemployed opiate-dependent adults. The Therapeutic Workplace is a novel employment based intervention that uses salary for work to reinforce clinically important behavior change;it has been shown effective in other applications. Drug abuse patients are hired and paid in this model workplace. To promote desirable behaviors, salary is made contingent both on work and on those other behaviors. Volunteer heroin dependent adults will be provided inpatient detoxification and naltrexone induction. Participants who complete the induction (N=80) will be prescribed depot naltrexone for 6 months, invited to work in the Therapeutic Workplace, and randomly assigned to one of two groups that will differ in the contingencies for working and earning salary. Patients in the "Workplace Plus Naltrexone Contingency" condition will earn access to the workplace and to earning salary by taking depot naltrexone once per month. "Workplace Plus Naltrexone Prescription" participants will be encouraged to take depot naltrexone, but access to working and earning salary will not be not contingent on doing so. Critical measures of acceptance of depot naltrexone and opiate use will be assessed over the 6-month trial. This study will provide a rigorous evaluation of a novel employment-based intervention, the Therapeutic Workplace, to promote use of depot naltrexone and to promote opiate abstinence in heroin dependent individuals who are at considerable risk for persistent and long-term opiate addiction.